This proposal is designed as a multidisciplinary approach to the study of neurotransmitter systems in the retina. The overall goal of this project is to a) identify the functional neurotransmitters in the retina, b) determine the cellular and subcellular localization of specific neurotransmitter systems and c) relate the biochemical and morphological characteristics of neurotransmitter systems to the current concepts of the physiology of vision. Biochemical techniques and assays have been developed by the principal investigator for qualitation and quantitation of uptake, storage, and release of neurotransmitter substances at the EM level. The success of these biochemical and microscopic techniques in brain preparations, and in results of preliminary retina studies, strongly demonstrated the effectiveness of these approaches in the proposed study. The proposed biochemical and microscopic studies will be correlated with a collaborative electrophysiological study of retina. The focus of these three areas of expertise on retinal transmitters will produce integrated information about chemical transmission as it functions in visual processing in retina.